This chapter presents an overview of micro- and small-sized financing schemes in the United States and Japan, highlighting their institutional frameworks, operational models, and target beneficiaries. It then offers a comparative analysis with Vietnam’s micro- and small-sized financing schemes, emphasizing both similarities and differences in structure and practice. Special attention is given to the various risk diversification approaches employed in the United States and Japan, such as collateral, due diligence, risk limiting, risk sharing, provisional funds, credit insurance, and secondary market. The chapter also compares these risk diversification approaches in the United States and Japan with those in Vietnam, identifying lessons that can be drawn from the experiences of both countries for Vietnam.